Download What is Cancer?

UNDERSTANDING CANCER
Cancer’s Seven
Warning Signs
What is
Cancer?
1. Change in bowel or bladder habits.
2. A sore that does not heal.
3. Unusual bleeding or discharge.
4. Thickening or lump in breast
or elsewhere.
5. Indigestion or difficulty in
swallowing.
6. Obvious change in wart or mole.
7. Nagging cough or hoarseness.
What is a
Carcinogen?
Cancer is a destructive
(malignant) growth of cells
which invades nearby tissues
and may metastasize (spread)
to other areas of the body.
Dividing rapidly, these cells
tend to be very aggressive and
out of control. In contrast, a
benign tumor is simply a
localized mass of slowly
multiplying cells resembling
its original tissue and are
seldom life-threatening.
Factors found in the environment which
may increase the risk of cancer are called
carcinogens. These include:
• Cigarrette Smoking
• Exposure to industrial
agents and chemicals
• Radiation
• Pollution
• Alcohol
• Some viruses
Normal cells
The Diagnosis
1.
How
Does
Cancer
Spread?
Most benign cells are considered harmless
unless their size or location threaten nearby
structures. Any sign of cancer should be
detected and treated early for a better
chance of a full recovery. The diagnosis of
malignant cancer is determined by a
microscopic examination of sampled
(biopsied) tissue. Measuring the extent the
cells have spread, called staging, can be
done using a variety of imaging techniques.
Computerized Axial Tomography
(CAT-scan) is a rotating X-ray machine used
to take cross-sectional pictures of specific
tumors. Magnetic Resonance Imaging (MRI)
uses a magnetic field and radiofrequency
waves to make detailed images of some
parts of the body, like the brain.
If you have a warning signal, see your doctor. Early
detection and self-examination are most important
in cancer detection.
Most experts believe that repeated or long
term exposure to these elements damages
normal cells. Heredity is another factor which
plays a role in the risk of breast, colon and
skin cancer.
Cancer cells
Precancerous cells
(from the American Cancer Society)
The venous system:
Cancer cells may travel
through the veins, often
to the liver and the lungs.
Cancer Incidence by Site and Sex
(based on information from the American Cancer Society)
*Excluding nonmelanoma skin cancer and carcinoma in situ.
3% Melanoma of the skin 3%
2% Oral 4%
Larynx 2%
4% Lymphoma 4%
19% Lung 11%
36% Breast
Stomach 3%
3% Pancreas 3%
2% Kidney 3%
14% Colon & Rectum 14%
4% Ovary
8% Uterus
2% Bladder 7%
Prostate 22%
2% Leukemia 3%
Superior
mesenteric
artery and vein
Middle colic vein
Cancer cells may
invade nearby tissues
or metastasize (spread)
to other organs. There
are three ways in which
cancer cells may move
to other tissues:
Transverse
colon
Ascending colon
The four stages of malignant cancer are
determined by the spread of the cancer
cells. This classification helps physicians
develop a treatment plan specific to each
individual cancer.
Lymph nodes
2.
Primary
cancer
Cancer
3.
Epithelium
The lymphatic system:
Cancer cells may move
through this series of
channels from the
tissues to lymph nodes
and eventually to the
circulatory system.
Seeding:
Cancer may penetrate
an organ, moving into
a body cavity (chest or
abdominal space) and
spread throughout
that area.
Lymph nodes
Liver
Lymph nodes
Pancreas
Metastatic
cancer
Metastatic cancer
in lymph nodes
Dermis
Stage I:
Bile duct
Lymph nodes
The cancer is small, localized
and limited.
Primary cancer
Metastatic cancer
Primary cancer
Stage IV:
Mammary ducts
Cancer
Treatments
Metastasis (spread) of the tumor
occurs in other tissues of the body.
Aorta
Mammary glands
Due to the variety of cancers, the ideal
treatment can range from observation to
complicated surgical removal with
aggressive therapy. Surgery, radiation
therapy and chemotherapy can be used
in combination or as individual
treatments. Some cancers may also be
treated with hormone or biological
therapy which can be described by a
physician. Successful treatment may
lead to remission (a condition when
signs of the disease are gone).
Left lung
Stage II:
Stage III:
Local spreading occurs in the organ
and lymph nodes.
Achieving a
Healthy Lifestyle
Cancer cells invade neighboring
tissues and lymph nodes.
Capillary
Normal cells
Surgery
Radiation beam
As a method of local treatment,
the diseased part of the body is
removed. Neighboring healthy
lymph nodes and tissues may
also be removed to help control
the spread of the cancer.
Chemotherapy
• Maintaining low body fat.
Epithelium
Radiation Therapy
9756
• Selecting a balanced diet high
in fiber, low in fat.
• Limiting alcohol intake.
Red blood cell
High energy rays, focused in a
beam, are used to damage the
cancer cells and stop their
reproduction. This local therapy
is used to shrink a cancer’s size
either before surgical removal or
after, to kill any remaining
cancer cells. Side effects may
range from minimal to moderate
including: tiredness, skin rashes,
and a decrease in infectionfighting white blood cells.
Cancer cells
Understanding cancer and its
cause is the best way to develop
a healthier lifestyle and avoid
exposure to its risks. Some
preventative measures include:
Chemotherapy
Normal cells
Cancer
Synthetic drugs, given
at prearranged, timed
intervals, are used to disrupt
a cancer cell’s ability to grow.
These drugs act, via the blood, on
the entire body. In addition to treating the
cancer, they may cause temporary side
effects in fast growing cells like those of the
blood, stomach and hair. Common side
effects are hair loss, nausea, vomiting and a
reduced number of white blood cells. These
side effects increase the chance of infection.
• Doing self examinations.
• Getting regular check-ups.
It is very important to follow
your physician’s instructions
and to seek the support of
family and friends.
Cancer-related support groups
are also available to discuss
issues surrounding cancer.
©1997, 1999 Anatomical Chart Co., Skokie, Illinois.
Medical Illustrations by Marguerite Aitken.